While a vehicle is being driven on a road, a driver changes road lanes based on road conditions or travelling directions. When changing lanes, the driver should check the state of other surrounding vehicles and the presence or absence of obstacles using left and right side-view and rear-view mirrors mounted on the vehicle, and execute a lane change when there is a clear gap and no risk of collisions with the other vehicles. A system for supporting an automatic lane change has been developed and applied to vehicles.
Further, a driving style varies according to a driver's personal disposition, but a currently proposed lane change control has been applied to vehicles based on uniform time and distance from a start time of the lane change control after a switch for lane change is turned on as illustrated in FIG. 1 of the prior art in the light of safety such as a safe distance from a vehicle approaching from behind rather than the driver's disposition, to a completion time thereof, irrespective of the driver's intention. Thus, such a lane change control may make aggressive drivers feel frustrated or could be perceived as too aggressive by more passive drivers according to the driver's disposition, making the drivers uncomfortable.